introduce loop calc demo service (#218)

* introduce loop calc demo service
* changelog
* fix changelog
* update image tag
* remove vscode config

changelog/v0.5.16/loop-demo.yaml

@@ -0,0 +1,3 @@
+changelog:
+  - type: NON_USER_FACING
+    description: Add a version of the calculator (service2) that produces 500s when the sum is in the range 500-600.

contrib/example/service2-500/Dockerfile

@@ -0,0 +1,7 @@
+FROM alpine:3.5
+
+COPY service2ise /service2ise
+
+ENTRYPOINT ["/service2ise"]
+
+EXPOSE 8080

contrib/example/service2-500/Makefile

@@ -0,0 +1,12 @@
+DOCKER_REPO ?= soloio
+VERSION ?= dev
+
+.PHONY: build
+build:
+	GOOS=linux CGO_ENABLED=0 go build -o service2ise -gcflags "-N -l" main.go
+	docker build -t $(DOCKER_REPO)/example-service2ise:$(VERSION) .
+
+.PHONY: push
+push: build
+	docker push $(DOCKER_REPO)/example-service2ise:$(VERSION)
+

contrib/example/service2-500/main.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/solo-io/go-utils/contextutils"
+)
+
+type Calculator struct {
+	Op1, Op2 int
+	IsAdd    bool
+}
+
+func main() {
+	http.HandleFunc("/calculate", calchandler)
+
+	contextutils.LoggerFrom(context.TODO()).Fatal(http.ListenAndServe(":8080", nil))
+}
+
+func calchandler(w http.ResponseWriter, r *http.Request) {
+	var req Calculator
+	dec := json.NewDecoder(r.Body)
+	err := dec.Decode(&req)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+	}
+
+	isadd := req.IsAdd
+	op1 := req.Op1
+	op2 := req.Op2
+	sum, err := computeSum(isadd, op1, op2)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		fmt.Fprintf(w, "%v", err)
+	}
+
+	fmt.Fprintf(w, "%d", sum)
+}
+
+func computeSum(isadd bool, op1, op2 int) (int, error) {
+	var val int
+	if isadd {
+		val = op1 + op2
+	} else {
+		val = op1 - op2
+	}
+	// Happy 5**th birthday Kubernetes! :D
+	if val >= 500 && val < 600 {
+		return 0, fmt.Errorf("result is a 500")
+	}
+
+	return val, nil
+}

contrib/example/service2-500/service2.yml

@@ -0,0 +1,33 @@
+apiVersion: apps/v1beta1
+kind: Deployment
+metadata:
+  name: example-service2
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: example-service2
+  template:
+    metadata:
+      labels:
+        app: example-service2
+    spec:
+      containers:
+      - name: example-service2
+        image: soloio/example-service2ise:0.1.0
+        ports:
+        - containerPort: 8080
+          protocol: TCP
+---
+kind: Service
+apiVersion: v1
+metadata:
+  name: example-service2
+spec:
+  selector:
+    app: example-service2
+  ports:
+    - name: http
+      protocol: TCP
+      port: 80
+      targetPort: 8080